Tool-holder.



M. W. SCHILLBERG.

TOOL HOLDER.

APPLICATION FILED MAILZI, I916.

Patented Jan. 30, 1917.

M W m w MELKER WILLARD SCHILIJBERG, OF NEW YORK, N. Y.

TOOL-HOLDER.

Specification of Letters Patent.

Patented J an. 30, 1917.

Application filed March 27, 1916. Serial No. 87,046.

To all whom it may concern:

Be it known that I, MELKER WVILLARD SCHILLBERG, a citizen of Sweden, and resident of the borough of Queens, in the county of Queens and State of New York, have invented certain new and useful Improvements in Tool-Holders, of which the following is a specification.

This invention relates to means for holding cutting devices, and appertains more especially to resilient' holders for such tools as are employed in doing lathe-work and the like.

One of the objects of the invention is to produce an improved holder of the nature set forth, wherein the tool will be carried in such a way as to yield or recede on a substantially straight line from the work, without chattering or producing an unevenly finished surface thereon, whenever a heavy out is made or unusually tough material is encountered.

A further object is the production of a tool holder of the character described, possessing means for tensionally limiting the amount of yield of the tool carrying part.

Another object is to provide a holder of the species mentioned, with a quick-acting, non-binding clamping device for the tool carried thereby.

Other objects and advantages of the in-- vention will become apparent as the specification proceeds.

With the aforesaid objects inview, the invention consists of the novel combinations and arrangements of parts hereinafter described in their preferred embodiments, pointed out in the subjoined claims, and illustrated in the annexed drawings, wherein like elements are designated by the same reference characters throughout.

In the said drawings :Figure 1 is a front vew of a holder made according to the invention, particularly adapted for a cutting-01f tool; Fig. 2 is a horizontal section of the same, on the irregular line 2-2 of Fig. 1, looking downward, as indicated by the arrows at the opposite ends of the latter named figure; Fig. 3 is a transverse section running vertically along the line 33 of Fig. 1, looking to the right, in the direction pointed out by the upper and lower arrows; Fig. 4 is a fragmentary view, showing a holder for a thread-cutting tool in front elevation, the clamping element being omitted; Fig. 5 is a fragmentary top plan View of the device shown in the preceding figure; and Fig. 6 is an end elevation of the same fdrm of the device, as seen from the left hand side of Fig. 4:.

In these views the numeral 11 denotes the shank of this improved tool-holder, the same being adapted for fastening in the usual manner in the tool post of a lathe, or similar machine. Integrally formed, preferably, with the said shank 11, is a tool carrying head 12, connected therewith by an upper portion 13, which may have a gooseneck.

shape, as shown. Below the said upper portion,vor under the gooseneck, the shank 11 and head 12 are separated by a narrow gap of peculiar formation, commencing as at 14, at the bottom edge of the holder, thence running approximately straight up to or slightly past the median plane of the head, and from that point on curving outward, both upwardly and downwardly as at 15 and 16, following substantially the course of an involute, which terminates at a point about midway between the center and the forward edge of the head, the latter joining the gooseneek at the narrowest part thereof, indicated by 17. Although the edges of the gap have been shown spaced substantially uniformly apart, it is understood that the same may be varied throughout the length of the gap. From this point the gooseneck gradually increases in size until it merges into the upper portion of the shank proper as at 18, where it attains its greatest width. By reason of the involute curvature of the gap here defined, its location and correlation to the gradually widening gooseneck cooperating therewith, the head 12 is enabled to yield or recede in such a way that a tool carried thereby will move straight rearwardly from the work, whenever necessary, without any appreciable dipping action, such as hitherto has been considered the inherent defect in known forms of tool-holders, where the bending moment originated farther rearward than in the present invention, or holders having widely open gaps and goosenecks of uniform dimensions. The aforesaid gap, consisting of the lines 14-15-16, can be produced either slot-like by a saw cut, in accordance with a process that is well understood, or else it may be formed in the manner suggested by dashand-dot lines at A, in Fig. 4. In the lat: ter case, the outwardly projecting part A? is forced back, of course, While in a hot state,and' separated from the other parts in rear thereof by an anti-weld spacer serving to keep them away at the proper d'istance for the entire width across the holder.

A lateral groove 25, extending longitudinally of the head 12, is provided for the" reception of a tool 26, the latter crossing the straight portion 14 of the before described involute gap or dividing line that separates the shank from the head, under clined and curved top portion and straight I vertical sides designed to receive a similarly shaped bolt-head 33, the lower side whereof conforms to the upper beveled edge of the tool 26. Due to the steeper pitch of the upper curved part of the bolt head 33, as shown in Fig. 3, a quick clamping action is obtained upon the tool without binding sidewise in the recess 32, when a nut, as 34, threaded upon the outwardly projecting end of the bolt 30 is tightened against the reverse side of the tool carrying head.

In order to provide a suitable clearance for the tool 26, the shank 11 is recessed as indicated at 38, Figs. 1 and 2. When the cutter 26 is of thin cross-section its inner side is made to bear against the rear wall of the recess 38, so as to receive support therefrom laterally.

eans are provided for pulling away the head 12, and tool therein, to a slight extent from the work piece operated upon, and

against the inherent resilience or, elasticity of the gooseneck 13, without affecting or altering the adjustment of the cross-slide of the lathe or other machine, on which the tool holder is supported in the usual manner, for instance by a suitable post or other clamping contriv'ance, These means prefer ably include as shown, a rod 40, anchored or fixed by a set screw 41, in the lower part of the head 12, and extending across the gap or slot 14, into the shank 11, through a clearance hole 42. The outer end of the rod 40 is threaded to receive a nut 43, which may be of the thumb or wing nut variety, and wherewith a suflicient strain can be exerted on the head 12 to pull it rearwardly. A spring 44, conveniently of the coil species, is lodged in a pocket 45 at the rear. end of. the shank 1 1, where it surrounds the rod 42. This spring has its termini bea'ring respectively against the inner wall of the pocket 45 and the base of the nut 43, and prevents the latter from shaking loose or from rattling while a heavy cut is being taken.

The thread cutting tool holder repre-' sented in Figs. 4, 5 and 6 is similar in most respects to the cutting-0E tool holder first herein described, and therefore nearly all of its constituent parts are designatedby the same numerals as an the preceding views. However, it embodies a few additional elements, such as ledges 50, 51 situated at the front and outer face of the holder, respectively, which afford a desirable support for the threading tool 26, the the latter being of less depth than the cutting off tool 26, and square in cross-section throughout. As shownin the said Figs. 4

to 6, the recess 38, in the shank 11, may be offset inwardly beyond the tool holding jaw 25, considering'that the tool is sufficiently stiff in a transverse direction. Fig. 4 further shows how a through pin 41 may be used, instead of the set screw 41, for anchoring the rod 40. 7

It is obvious, notwithstanding the tool holding jaws are shown as being of either dovetail or square formation, any other suitable shape thereof can be employed depending of course, upon the section of the tools held therein.

While certain preferred embodiments of desire to secure by Letters Patent and claim is 1. A tool holder comprising a shank, a tool carrying head separated therefrom by a gap ending with an approximately involute curve terminating forward in the upper part of said head, and means for securing the tool substantially central in the latter within said curve.

2. A tool holder comprising a shank portion, a tool carrying head, means for securing the tool approximately in the center of the latter, and a graduallyincreasing connecting member intermediate the head and shank portion leaving a gap therebetween of substantially involute curvature terminating outwardly forward past said center. 7

3. A tool holder comprising a shank,.a tapering gooseneck extending forwardly, a tool carrying head divided from said shank by a narrow gap following the curvature of said gooseneck, and means for securing the tool to the central portion of said head within said curvature.

t. A tool holder comprising a shank, an upwardly and outwardly extending yieldable member joined at one end to said shank, a tool carrying head formed integral with the other end of said member, said head consisting of a part forced adjacent to the underside of the member and to the end of the shank so as to leave a narrow gap therebetween following the inner contours of the last named elements.

5. A tool-holder comprising a shank, a tool carrying head separated therefrom by a dividing gap, a connecting member between said shank and said head, and means for drawing the latter against its inherent resilience or elasticity to close said gap.

6. A tool-holder comprising a shank portion, a tool carrying head separated by a gap therefrom, a member connecting said head with said shank portion forwardly of said gap, a tensioning element anchored in the head and extending rearwardly through the shank, and a resilient device interposed between the rear end of the latter and said element to produce an initial strain thereon.

7. A tool holder comprising a shank, a-

tool carrying head resiliently connected thereto, a rod fastened to said head and passing through said shank, the rear end of the latter being provided with a recess, a nut at the end of said rod for exerting a pull on the head against its resiliency, and a spring in said recess adapted to receive the initial thrust of said nut.

8. A tool holder comprising a shank provided with a recess, a tool carrying head having a seat for the tool in approximate alinement with said recess, a member yieldingly connecting said shank with said head but leaving a gap therebetween, the latter extending in a substantially perpendicular direction from one edge of the shank to a point above said seat and thence following the configuration of said member, and means for clamping the tool on its seat so as to leave it free to move in the recess when the member yields under pressure.

9. A tool holder comprising a shank, a tool carrying part, and a curved member connecting said shank to said part but separated by a narrow gap therefrom, said gap extending substantially straight to a point about half way of its length from one edge of the shank and thereafter following ap proximately the curve of said member, the tool' carrying part being formed with a re cess having its upper edge curved in the same general direction as the latter half of the gap while its sides are in parallelism with the straight portion thereof, combined with a head shaped to correspond to said recess and to one edge of the tool, said head being adapted to clamp the latter to the carrying part.

10. A tool holder comprising a shank, an integral gooseneck commencing with a wider section at said shank and extending upwardly and outwardly therefrom in curved tapered formation, and a tool carrying head united at the narrowest portion with said gooseneck and separated from the latter by a narrow gap of similar curvature, the said portion being so positioned that the combined bending actions between said head and the gooseneck will cause a tool carried by the former to recede substantially straight toward the shank when subjected to strain.

Signed at the borough of Manhattan in the county of New York and State of New York this 25th day of March A. D. 1916.

MELKER WILLARD SCHILLBERG.

Witnesses H. C. KARLsoN, W. H. GEE.

copies of this patent may be obtained tor five cents each, by addressing the Commissioner of Patents,

Washington, D G. 

